As usual, a base of an external antenna secures the objects by bolting; a lug and a bolt are combined to screw the antenna base on the surface of the objects. Before being screwed with a bolt, a threaded bolt bore is drilled on the surface of the objects. Thus drilling causes rust and undergoes destructive changes for a planish, smooth looking on the surface of the objects. To assemble and detach a lug bolt is a difficult, troublesome task.
Or a base of an external antenna secures the objects by clamping. The clamp is easy to damage the lacquer, paint or coating on the surface of the objects. Detach the clamp from the objects is a tiresome work.
Or a base of an external antenna secures the objects by magnet. The magnet is lack of attraction for nonmetallic materials; the magnetic field interference may lead to distortion of the waveform or noise of the voice frequency with the electronic products. The magnet must keep away from electronic products.
Or a base of an external antenna secures nonmetallic objects by sucking disk. The surface of the nonmetallic objects must be a delicate flat and waxen-like in appearance. Otherwise, the sucking disk sticks to the surface only in a short time. The external antenna will be dropped off the nonmetallic surface.
Point against the aforesaid defects, how to design a portable, separable external antenna, being avoid from magnetic field interference about electronic products, and attached to the surface of the objects (metallic or nonmetallic) as an joint base will be concerned by the inventor of the present invention.